1. Field of the Invention
The present invention relates to a magnetic head including a slider for use in a hard disk device, and a method for manufacturing the magnetic head and, more particularly, to a magnetic head which incurs less damage in the course of recording and/or reproduction on a recording medium, and to a method for manufacturing the magnetic head.
2. Description of the Related Art
FIG. 17 is a perspective view of a conventional magnetic head for use in a hard disk, with a medium-facing surface looking upwardly.
In this magnetic head, an upstream end A in the direction of motion of a recording medium is referred to as a leading edge and a downstream end B thereof is referred to as a trailing edge.
Referring to FIG. 17, a slider 1 is fabricated of a ceramic material. Thin-film elements 6 for magnetic recording and magnetic reproduction are arranged on the trailing end face B of the slider 1.
An air groove 2 is formed on a medium-facing surface of the slider 1, and an ABS (Air Bearing Surface) surface 3 surrounds the air groove 2. The ABS surface 3 is crown-shaped.
The conventional magnetic head shown in FIG. 17 has edges 1a and 1a on the medium-facing surface of the slider 1. When the magnetic head comes into contact with the recording medium, the recording medium is subject to damage. The edges 1a and 1a of the slider 1 are thus chamfered through a machining process.
The chamfering of the edges 1a and 1a is performed on a plurality of sliders 1 in their unitary body, i.e., a slider bar. FIG. 18 is a partial perspective view showing the slider bar of FIG. 17
As shown in FIG. 18, the trailing end face B of the slider bar 7 has a plurality of thin-film elements 6. The medium-facing surface 8 of the slider bar 7 bears the air groove 2 and the ABS surface 3, and a notch 9 having a predetermined depth is formed between the thin-film elements 6.
FIG. 19 is a front view showing a conventional chamfering process. The entire surface of the air groove 2 and the ABS surface 3 in the slider bar 7 fixed onto a jig 10 are put into contact with a lapping tape R for polishing arranged on a cushioning material K by a certain level of pressure. By sliding the jig 10 in the X direction and/or Y direction, the edges are chamfered.
No consideration has been given to what degree of chamfering is effective in the reduction of damage to the recording medium when the edges are chamfered. When the slider is chamfered using the above-referenced chamfering process, maintaining chamfering accuracy is difficult.
Accordingly, it is an object of the present invention to provide a magnetic head in which chamfering dimensions of edges of a medium-facing surface of a slider fall within a range which allows the damage of the recording medium to be reduced with the magnetic head coming into contact with the recording medium, and which reduces variations in chamfering performance.
The present invention in one aspect relates to a magnetic head and includes a slider including a medium-facing surface oriented toward a recording medium, a supporting surface serving as a support, a trailing end face and a leading end face, and an element, arranged on the trailing end face of the slider, for magnetically recording and/or magnetically reproducing data, wherein at least one of the trailing edge and the leading edge of the medium-facing surface has a tapered surface or a curved surface having a first border line bordering the medium-facing surface and a second border line bordering one of the trailing end face and the leading end face, and wherein an imaginary plane in which the first border line and the second border line lie makes an angle of not less than 5 degrees but not more than 14 degrees with respect to the supporting surface.
When the tapered surface or the curved surface is formed on at least one of the trailing edge and the leading edge of the medium-facing surface, the imaginary plane in which the first border line and the second border line lie makes an angle of not less than 5 degrees but not more than 14 degrees with respect to the supporting surface. In this arrangement, the occurrence of damage to the recording medium is reduced when the magnetic head comes into contact with the recording medium, and variations in chamfering performance are reduced.
When the angle xcex8 between the supporting surface and the imaginary plane in which the first border line and the second border line lie falls within a range of 5xc2x0xe2x89xa6xcex8xe2x89xa68xc2x0, the occurrences of damage when the magnetic head comes into contact with the recording medium are completely prevented.
Preferably, a protective layer is formed on the medium-facing surface.
Preferably, the first border line of the tapered surface or the curved surface formed on the trailing edge is positioned to be closer to the trailing end face than a gap of the element. In this arrangement, the occurrence of damage of the element is avoided.
Preferably, the medium-facing surface includes a step, and the highest surface area of the medium-facing surface is an ABS surface receiving a lift resulting from an air flow on the recording medium, and the gap of the element is located within the region of the ABS surface. In the arrangement, the element is placed closest to the recording medium during recording and reproduction.
The first border line runs along a border between one of the tapered surface and the curved surface and the ABS surface.
Preferably, the first border line of the tapered surface or the curved surface formed on the leading edge is positioned to be closer to the leading end face than a step defining the ABS surface. In this arrangement, lift characteristics of the magnetic head is thus free from the tapered surface or the curved surface.
The first border line may extend in a straight line or a curved line in the transverse direction of the slider.
The present invention in another aspect relates to a method for manufacturing a magnetic head which includes a slider including a medium-facing surface oriented toward a recording medium, a supporting surface serving as a support, a trailing end face and a leading end face, and an element, arranged on the trailing end face of the slider, for magnetically recording and/or magnetically reproducing data. The method includes the steps of (a) producing a slider bar having a plurality of elements on the trailing end face thereof, (b) forming a tapered surface on the edge of the trailing end face by setting the edge of the medium-facing surface of the slider bar on the trailing edge on a polishing surface so that the supporting surface of the slider bar makes an angle not less than 5 degrees but not more than 14 degrees with respect to the polishing surface, and by moving the slider bar reciprocatingly in one direction, and (c) separating the slider bar into individual sliders each having the element thereof.
Preferably, the manufacturing method further includes, subsequent to the tapered surface forming step (b), (d) forming a tapered surface on the edge of the leading end face by setting the edge of the medium-facing surface of the slider bar on the leading edge on a polishing surface so that the supporting surface of the slider bar makes an angle not less than 5 degrees but not more than 14 degrees with respect to the polishing surface, and by moving the slider bar reciprocatingly in one direction.
Since a flat-tapered surface is formed on the slider trailing edge and/or the slider leading edge, controlling variations in the dimensions of the taper such as the angle of the taper and the range of the taper becomes easier.
Preferably, in the step (b) and/or the step (c), the angle between the supporting surface of the slider bar and the polishing surface is set to be an angle not less than 5 degrees but not more than 14 degrees.
When the edges of the slider bar are polished with the angle between the supporting surface of the slider bar and the polishing surface set to be an angle not less than 5 degrees but not more than 14 degrees, an imaginary plane in which the first border line and the second border line lie makes an angle of not less than 5 degrees but not more than 14 degrees with respect to the supporting surface. The first border line runs along the border between the medium-facing surface and the tapered surface formed on the slider trailing edge and/or the slider leading edge, and the second border line runs along the border between the tapered surface and the end face. The occurrences of damage to the recording medium when the magnetic head comes into contact with the recording medium are reduced. Variations in the chamfering process are minimized.
When the slider bar is reciprocatingly moved with the angle between the supporting surface of the slider bar and the polishing surface kept to within a range of not less than 5 degrees to not more than 8 degrees, an imaginary plane in which the first border line and the second border line lie makes an angle of not less than 5 degrees to not more than 8 degrees with respect to the supporting surface. The first border line runs along the border between the mediumxe2x80x94medium-facing surface and the tapered surface formed on the slider trailing edge and/or the slider leading edge, and the second border line runs along the border between the tapered surface and the end face. The occurrences of damage to the recording medium when the magnetic head comes into contact with the recording medium are prevented.
When the slider bar is reciprocatingly moved with the angle between the supporting surface of the slider bar and the polishing surface kept to within a range from not less than 5 degrees to not more than 14 degrees, an overall distance of travel of the slider bar in reciprocating motion for forming the tapered surface is reduced. Workability with the slider bar is thus improved.
When the slider bar is reciprocatingly moved with the angle between the supporting surface of the slider bar and the polishing surface kept to within a range from not less than 5 degrees to not more than 8 degrees, workability with the slider is even more improved.
The slider bar may be reciprocatingly moved in a direction parallel to or perpendicular to the longitudinal direction of the slider bar in the step (b) and/or the step (c).
When the slider bar is reciprocatingly moved in a direction parallel to the longitudinal direction of the slider bar, the first border line, running along the border between the mediumxe2x80x94medium-facing surface and the tapered surface formed on the trailing edge and/or the leading edge of the finished slider, extends in a straight light or a curved line in the transverse direction. Variations in the dimensions of the tapered surface are controlled.
A protective layer may be formed on the medium-facing surface oriented toward a recording medium bar before the step (b) and/or the step (c).
Since the entire medium-facing surface of the slider is put into contact with the lapping tape in the conventional chamfering process, the protective layer formed on the medium-facing surface is polished together.
In accordance with the present invention, only the trailing edge and/or the leading edge of the slider bar is put into contact with the polishing surface in a polishing operation. The protective layer formed on the medium-facing surface is thus free from polishing, except the edges of the slider.